Tool



June 2; 1953 H. H. MANNING 2, 1

- TOOL Filed July 9. 1951 Sunenfor Gttorneg Patented June 2, 1953 Champion De Arment Tool Company, Meadville, Pa., a corporation of Pennsylvania Application July 9, 1951, Serial No. 235,800

3 Claims. 01. s1-51.3)

1 This application is a continuation-in-part of application Serial No. 120,309, filed October 8, 1949.

This invention relates to hand tools, such as pliers, having crossed members pivoted by tongue and groove joint elements. In the preferred form there are a plurality of joint elements on one of the members which are selectively usable for different jaw openings. In such tools it is desirable that the jaws work freely, particularly in the opening direction, and that the tools be of light weight' so as to be easily handled. It is also desirable that the jaws remain in alignment under working pressure. Thisinvention is intended to achieve these objects by having the tongue and groove elements formed by intermeshing arcuate ribs converging from the base or root toward the crest and with the engaging faces on the pressure side inclined or undercut so as to cause the jaw members to clingtogether. The converging at the crests results in greater strength and ease of opening. The undercutting of the pressure faces holds the jaws in alignment under working pressure.

In the drawing,- Fig. l is a side view of a pair of pliers, Fig. 2 is a section on line 22 of Fig. l, and Fig. 3 is a fragmentary section illustrating the operation. 7

The invention is shown applied to a tool of the construction illustrated in my Patent 1,950,362. As there shown, the tool comprises crossed pivoted members I. and 2 respectively provided with jaws 3 and 4 at one side of a bolt 5 extending through an opening 6 in the member 2, and through a slot I in the member I. On the opposite side of the bolt, the members are provided with handles 8 and 9. On the member 2 is an arcuate rib II] receivable in any one of a plurality of arcuate grooves II in the member I. The width of the jaw opening is adjusted by sliding the member 2 carrying the bolt 5 along the slot 1 until the pointed or beveled end I2 of the rib Ill comes opposite the desired groove II. From one aspect the rib III and groove II are tongue and groove joint elements on adjacent faces of the members I and 2. The beveled end l2 tends to lead the rib into the desired groove.

Under working conditions it is desirable that the jaws 3 and 4 remain in essentially the same plane so that the gripping surfaces will oppose each other. Lateral offsetting of one of the jaws relative to the other which would tend to move the gripping surfaces of the jaws out of opposed relation and to disengage the tongue and groove elements is undesirable. In the present construction lateral offsetting is prevented by making both the tongue and groove elements I0 and II with inclined or undercut sides or faces Illa, IIa on-the working pressure side.

the members to cling together.

Only a very slight inclination is necessary to provide the interlock against lateral off-setting. If preventing lateral off-setting is-not desired, the faces Illa, Ila can be at right angles tothe jaw" members I and 2.

The opposite faces IlIb, IIb, which do notenj gage under working pressure, have a pronounced slope (greater than the slope of the faces Illa, Na) in the direction to cause spreading'rather .1 than clinging if these faces should engage. This 7 results in the rib Ill and the ribs I3 forming the grooves I I each converging from wider bases I00,

I30 toward narrower crests Illd and I3d, which are the narrowest portions of the ribs.

IIb should be engaged, the spreading resulting from the slope of the faces would automatically increasethe clearance between the ribs I0 and I3,

or crests of the ribs which are narrowest are, subjected to the least stress. The wider bases of the ribs which are subjected to the greatest stress have sections in proportion to the greater stress.

The freedom from binding and from lateral off-setting of the jaws is obtained even if the jaws are temporarily off-set by a twisting force applied during use or are permanently off-set by one of the jaws becoming bent by abuse.' When the jaws are off-set, for any reason, the rib Ill merely meshes or penetrates less deeply into the selected groove II. With the lesser penetration of the rib I0 into the selected groove II, there is a greater clearance between the rib and groove which prevents binding.

It is essential that the pin 5 be freely slidable lengthwise but not cross-wise of the slot 1.

The action under the forces present during opening and closing of the jaws is illustrated in Fig. 3. When the jaws are being closed, there is a force exerted on jaw 3 in the direction of arrow I4 and a force exerted on jaw 4 in the direction of arrow I5. These forces tend to bring The faces Ina, i I la, which engage in any selected position of the pliers are slanted in the direction to provide an interlock preventing lateral off -setting movements. of the jawsrelative to each other. The engaging pressure on faces Illa, Ila exerts a force causing i This force is .only present when the jaws are under pressure.

I At the f start of the opening stroke, if the faces Illb and] the selected groove. During opening of the jaws,

the forces tend to be in the opposite direction as indicated by the arrows Ma, [5a bringing the faces lBb, llb into engagement and resultingin a spreading force on the member I in the direction of arrow 16a. This spreading force is in the direction-to decrease the penetration of the rib [0 or in the direction to increase the clearance between the rib and groove.

This insures free or easy opening of the jaws which is desirable in tools of this type.

The free lengthwise sliding of the pin in the slot prevents interference of the faces a, Ha, when the rib [0 only partially penetrates the depth of the selected groove. The lack of crosswise movement of the pin in the slot keeps the rib .and groove centered so binding or locking of the jaws under pressure is prevented, such binding being due to a pivoting about a point of engagement of the rib and groove.

What is claimed as new is:

1. In a tool having a pair of crossed members, work engaging surfaces on the members, and a pivotal joint between the members comprising a pin and slot connection preventing lateral shifting of one member relative to the other in a direction crosswise of the slot but freely permitting movement of one member relative to the other lengthwise of the slot, said pivotal joint including interfitting concentric arcuate tongue and groove elements of substantially the same radius respectively on adjacent faces of the members, the elements being formed of arcuate ribs of the same radius on said adjacent faces, one rib being on' one of the adjacent faces and a plurality of ribs being on the other of the adjacent faces the ribs converging in cross section from wider bases toward narrower crests with abrupt arcuate faces on the sides 'of the ribs engaging under pressure and with arcu'ate faces on the sides of the ribs which do not engage under working "pressure sloped in the direction to cause spreading.

2. In a tool having a pair of crossed members,

work engaging surfaces on the members, and a pivotal joint between the members comprising a pin and slot connection preventing lateral shifting of one member relative to the other in a direction crosswise of the slot but freely permitting movement of one member relative to the other lengthwise of the slot, said pivotal joint including interfitting concentric arcuate tongue and groove elements of substantially the same radius respectively on adjacent faces of the members,

the elements being formed of arcuate ribs of the same radius on said adjacent faces, one rib being on one of the adjacent faces and a plurality of ribs being on the other of the adjacent faces the ribsconverging in cross section from wider bases toward narrower crests with arcuate faces on the sides of the ribs engaging under working pressure undercut to cause the engaged faces to cling together'under working pressure and with arcuate faces on the sides of the ribs which do not engage under working pressure sloped in the direction to cause spreading.

3. In a tool having a pair of crossed members, work engaging surfaces on the members, and a pivotal joint between the members comprising a pin and slot connection preventing lateral shifting of one member relative to the other in a direction crosswise of the slot but freely permitting movement of one member relative to the other lengthwise of the slot, said pivotal joint including interfittingconcentric arcuate tongue and groove elements of substantially the same radius respectively on adjacent faces of the members, the elements being formed of arcuate ribs of the same radius on said adjacent faces, one rib being on one of the adjacent faces and a plurality of ribs being on the other of the adjacent faces, said ribs having arcuate faces on the sides engaging under working pressure undercut to cause the engaged faces to cling under working pressure.

HOWARD H. MANNING.

References Cited in the file of this patent UNITED STATES PATENTS Sweden July 18, 1.940 

